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At least 1,135 records · Page 63Linked to original sources
PubMed2003

Reliability, validity, and classification accuracy of a measure of DSM-IV diagnostic criteria for pathological gambling.

OBJECTIVE: The purpose of this study was to measure the reliability, validity, and classification accuracy of the DSM-IV diagnostic criteria for pathological gambling. METHOD: Participants in this study were drawn from two sources: 803 men and women from the general adult population of Minnesota and 259 men and women who were admitted to a gambling treatment program. A 19-item measure of the DSM-IV diagnostic criteria for pathological gambling was administered, along with other validity measures. RESULTS: The DSM-IV diagnostic criteria were found to be reliable and valid. With a standard cutoff score of 5, DSM-IV criteria yielded satisfactory classification accuracy results; however, a cutoff score of 4 made modest improvements in classification accuracy and, most important, reduced the rate of false negatives. CONCLUSIONS: The DSM-IV diagnostic criteria for pathological gambling, when operationalized into questions, demonstrated satisfactory reliability, validity, and classification accuracy, and a cutoff score of 4 improved diagnostic precision.

Adolescent↗
PubMedDate not supplied

A new logistic regression approach for the evaluation of diagnostic test results.

The value of a dichotomous diagnostic test is often described in terms of sensitivity, specificity, and likelihood ratios (LRs). Although it is known that these test characteristics vary between subgroups of patients, they are generally interpreted, on average, without considering information on patient characteristics, such as clinical signs and symptoms, or on previous test results. This article presents a reformulation of the logistic regression model that allows to calculate the LRs of diagnostic test results conditional on these covariates. The proposed method starts with estimating logistic regression models for the prior and posterior odds of disease. The regression model for the prior odds is based on patient characteristics, whereas the regression model for the posterior odds also includes the diagnostic test of interest. Following the Bayes theorem, the authors demontsrate that the regression model for the LR can be derived from taking the differences between the regression coefficients of the 2 models. In a clinical example, they demonstrate that the LRs of positive and negative test results and the sensitivity and specificity of the diagnostic test varied considerably between patients with different risk profiles, even when a constant odds ratio was assumed. The proposed logistic regression approach proves an efficient method to determine the performance of tests at the level of the individual patient risk profile and to examine the effect of patient characteristics on diagnostic test characteristics.

Angiography↗
PubMedDate not supplied

The efficacy of diagnostic imaging.

The authors discuss the assessment of the contribution of diagnostic imaging to the patient management process. A hierarchical model of efficacy is presented as an organizing structure for appraisal of the literature on efficacy of imaging. Demonstration of efficacy at each lower level in this hierarchy is logically necessary, but not sufficient, to assure efficacy at higher levels. Level 1 concerns technical quality of the images; Level 2 addresses diagnostic accuracy, sensitivity, and specificity associated with interpretation of the images. Next, Level 3 focuses on whether the information produces change in the referring physician's diagnostic thinking. Such a change is a logical prerequisite for Level 4 efficacy, which concerns effect on the patient management plan. Level 5 efficacy studies measure (or compute) effect of the information on patient outcomes. Finally, at Level 6, analyses examine societal costs and benefits of a diagnostic imaging technology. The pioneering contributions of Dr. Lee B. Lusted in the study of diagnostic imaging efficacy are highlighted.

Clinical Protocols↗
PubMedDate not supplied

Information gathering and integration as sources of error in diagnostic decision making.

This research examined the relative importance of information gathering versus information utilization in accounting for errors in diagnostic decision making. Two experiments compared physicians' performances under two conditions: one in which they gathered a limited amount of diagnostic information and then integrated it before making a decision, and the other in which they were given all the diagnostic information and needed only to integrate it. The physicians: 1) frequently failed to select normatively optimal information in both experimental conditions; 2) were more confident about the correctness of their information selection when their task was limited to information integration than when it also included information gathering; and 3) made diagnoses in substantial agreement with those indicated by applying normative procedures to the same data. Physicians appear to have difficulties recognizing the diagnosticity of information, which often results in decisions that are pseudodiagnostic or based on diagnostically worthless information.

Bayes Theorem↗
PubMedDate not supplied

Is the defensive use of diagnostic tests good for patients, or bad?

Physicians sometimes order diagnostic tests to reduce the risk of malpractice liability. The authors develop an expected-utility model that links a rational physician's concerns about malpractice liability to increases in the use of diagnostic tests and use this model to assess the effects of defensive testing on patients' interests. To do so, they adapt the threshold approach to clinical decision making to incorporate the physician's interests, focusing on 1) the effect of the physician's expected liability risks and 2) the effect of any expected liability reduction due to diagnostic testing. Surprisingly, the mere existence of liability risks is often sufficient to widen the range of disease probabilities for which diagnostic testing is the preferred clinical strategy. If testing reduces the physician's expected liability risks, the testing range is widened further. For some disease probabilities, testing is preferred by the physician even though it is not in the patient's best interests. When tests are performed in such instances, utility is transferred from the patient to the physician and the physician's insurer. Although the defensive use of diagnostic tests improves clinical outcomes for some patients, it worsens clinical outcomes for others. Moreover, defensive testing worsens the expected outcomes of all patients whose clinical strategies are changed. Physicians should realize that defensive testing necessarily reduces the overall quality of patient care.

Decision Making↗
PubMed1999

Tuberous Sclerosis Consensus Conference: recommendations for diagnostic evaluation. National Tuberous Sclerosis Association.

At the recent Tuberous Sclerosis Consensus Conference, a subcommittee proposed recommendations to guide the rational use of diagnostic studies in patients with tuberous sclerosis complex. Recommendations were made for diagnostic evaluation at the time of diagnosis, when testing helps both to establish the diagnosis and to identify potential complications. Additional guidelines were proposed for the ongoing surveillance of established patients to detect later complications of tuberous sclerosis complex. In the absence of comprehensive population studies to govern the use of diagnostic studies in individuals with tuberous sclerosis complex, the panel developed guidelines based on the disorder's natural history, concentrating on complications that are common, clinically significant, and more easily managed when found early. Finally, the group made suggestions for the use of diagnostic tests to identify family members who have tuberous sclerosis complex. Although these recommendations should standardize and improve our use of diagnostic studies in individuals with tuberous sclerosis complex, the clinical approach in a given patient must remain flexible enough to meet the needs of individual patients and families.

Adult↗
PubMed1993

Reliability and validity of diagnostic modalities for temporomandibular disorders.

Temporomandibular disorders (TMD) encompass a group of musculoskeletal conditions that involve the temporomandibular joint (TMJ) or joints, the masticatory musculature, or both. These conditions are typically characterized by pain in the pre-auricular area that is usually aggravated by chewing or other jaw function and is often accompanied, either singly or in combination, by limitation of jaw movement, joint sounds, palpable muscle tenderness, or joint soreness. As with most other musculoskeletal conditions, the diagnostic "gold standard" for TMD is based upon an evaluation of the patient's history and clinical examination, supplemented, when appropriate, by TM joint imaging. It is against this "gold standard" that the reliability and validity of diagnostic modalities must be compared. With regard to electronic devices, several reviews of the scientific literature have concluded that the diagnostic reliability, validity, sensitivity, and specificity of such devices in the diagnosis of TMD have not been established. In addition, although clinical examination of the dentition may provide useful diagnostic information for some conditions, specific occlusal relationships have poor sensitivity and specificity when related to the presence or absence of TMD. TMJ imaging, when indicated, is useful in the detection of pathology within the joint, provided that validated criteria are applied to an analysis of the image. However, the assessment of condylar position as a diagnostic criterion for TMD has very poor reliability and validity.

Diagnostic Imaging↗
PubMed2002

Logistics of referral, diagnostic assessment and treatment of patients with breast symptoms and signs.

BACKGROUND AND AIMS: The logistics of diagnosis and treatment in a hospital with slightly above 400 new cases of breast cancer per year is analysed. MATERIALS AND METHODS: The patient flow from referral, through the diagnostic procedures and through surgical treatment is described. RESULTS AND CONCLUSIONS: The basic principle of the diagnostic assessment is the triple diagnostic procedure including mammography supplemented by ultrasonography, fine needle aspiration cytology and clinical examination. The radiologist and pathologist are working together in the breast diagnostic centre and are thus able to give a "single visit diagnosis" in most cases. The surgeon sees the patient either the same day or the next. A "consensus meeting" held each week with representatives for all specialities present has an important function in quality assurance and education. If one or more of the triple diagnostic components reach conclusion level "suspicious lesion", surgery is indicated. In hospital management is based on day surgery for all biopsies, wide excisions with or without sentinel node and some ablatio simplex mammae. For wide excision and ablation with complete axillary node clearance, the patients are transferred from the day surgery unit to a patient hotel after 3-4 hours of observation and stay till the drain can be removed. Only in rare case of high cardiopulmonary risk, beds in ordinary wards are used. This is a highly cost efficient logistic saving the hospital approximately 400,000 EUR a year compared to ordinary in hospital treatment.

Breast Neoplasms↗
PubMed2004

Diagnostic approach to the patient with jaundice following trauma.

BACKGROUND AND AIMS: Jaundice in trauma patients may reflect serious underlying pathology. The aim of this review was to determine the appropriate diagnostic approach to the patient with jaundice following trauma. METHODS: A MEDLINE search was performed to retrieve publications which outlined the causes of jaundice in trauma patients. RESULTS: The main causes of jaundice in trauma patients were found to be bilirubin overload caused by breakdown of transfused- and extravasated blood and hepatic dysfunction caused by sepsis, infections, initial shock and systemic hypotension. Bile duct injury or drug induced liver injury are rare. Liver function tests are often uninformative but commonly show a cholestatic pattern. Ultrasound, CT or ERCP are the diagnostic imaging methods most widely used. Abdominal ultrasound and CT may reveal specific organ injuries, bile duct dilatation, intraabdominal fluid collections, hematomas or acalculus cholecystitis. ERCP is often diagnostic and permits a therapeutic intervention when a bile duct injury is present. CONCLUSIONS: The primary aim of the diagnostic approach should be to identify all cases of bile duct injury or obstruction. Sepsis and infections should be actively looked for. The number of blood transfusions must be calculated. Ultrasound, CT or ERCP are the diagnostic imaging methods most widely used.

Bile Ducts↗
PubMed2002

Conducting systematic reviews of diagnostic studies: didactic guidelines.

BACKGROUND: Although guidelines for critical appraisal of diagnostic research and meta-analyses have already been published, these may be difficult to understand for clinical researchers or do not provide enough detailed information. METHODS: Development of guidelines based on a systematic review of the evidence in reports of systematic searches of the literature for diagnostic research, of methodological criteria to evaluate diagnostic research, of methods for statistical pooling of data on diagnostic accuracy, and of methods for exploring heterogeneity. RESULTS: Guidelines for conducting diagnostic systematic reviews are presented in a stepwise fashion and are followed by comments providing further information. Examples are given using the results of two systematic reviews on the accuracy of the urine dipstick in the diagnosis of urinary tract infections, and on the accuracy of the straight-leg-raising test in the diagnosis of intervertebral disc hernia.

Diagnostic Techniques and Procedures↗
PubMed2005

No role for quality scores in systematic reviews of diagnostic accuracy studies.

BACKGROUND: There is a lack of consensus regarding the use of quality scores in diagnostic systematic reviews. The objective of this study was to use different methods of weighting items included in a quality assessment tool for diagnostic accuracy studies (QUADAS) to produce an overall quality score, and to examine the effects of incorporating these into a systematic review. METHODS: We developed five schemes for weighting QUADAS to produce quality scores. We used three methods to investigate the effects of quality scores on test performance. We used a set of 28 studies that assessed the accuracy of ultrasound for the diagnosis of vesico-ureteral reflux in children. RESULTS: The different methods of weighting individual items from the same quality assessment tool produced different quality scores. The different scoring schemes ranked different studies in different orders; this was especially evident for the intermediate quality studies. Comparing the results of studies stratified as "high" and "low" quality based on quality scores resulted in different conclusions regarding the effects of quality on estimates of diagnostic accuracy depending on the method used to produce the quality score. A similar effect was observed when quality scores were included in meta-regression analysis as continuous variables, although the differences were less apparent. CONCLUSION: Quality scores should not be incorporated into diagnostic systematic reviews. Incorporation of the results of the quality assessment into the systematic review should involve investigation of the association of individual quality items with estimates of diagnostic accuracy, rather than using a combined quality score.

Bias↗
PubMed2003

Influence of Alzheimer pathology on clinical diagnostic accuracy in dementia with Lewy bodies.

OBJECTIVE: To determine whether AD neurofibrillary pathology influences clinical diagnostic accuracy in dementia with Lewy bodies (DLB). BACKGROUND: Pathologic diagnosis of DLB mandates Lewy bodies but also allows for AD pathology in the form of plaques and tangles. Because clinical diagnostic accuracy of DLB remains low, the authors questioned whether the severity of AD pathology in the form of tangles might affect the clinician's ability to correctly diagnose DLB in life. DESIGN/METHODS: Ninety-eight subjects with autopsy-proven DLB who had been evaluated annually at the University of California San Diego AD Research Center were identified. The clinical diagnosis used was the last diagnosis before death. Pathologic diagnosis of DLB was made according to Consensus guidelines, and Braak staging was used to assess the degree of neurofibrillary AD pathology. The clinical characteristics of subjects with DLB with low vs high Braak stages were compared and the clinical diagnostic accuracy for subjects stratified according to Braak stage was determined. RESULTS: Only 27% of the subjects with DLB demonstrated both visual hallucinations and spontaneous extrapyramidal signs (EPS). The low Braak stage (0 to 2, n = 24) subjects had a higher frequency of visual hallucinations (65%) than did subjects with DLB with higher (3 to 6, n = 66) Braak stages (33%, p = 0.008), and showed a slightly greater but not significant degree of EPS. Although clinical diagnostic accuracy for DLB was relatively low (49%), it was higher for subjects with low (75%) compared to high (39%) Braak stages (p = 0.0039). CONCLUSIONS: The degree of concomitant AD tangle pathology has an important influence on the clinical characteristics and, therefore, the clinical diagnostic accuracy of DLB.

Aged↗
PubMed2006

The quality of diagnostic accuracy studies since the STARD statement: has it improved?

OBJECTIVE: To assess whether the quality of reporting of diagnostic accuracy studies has improved since the publication of the Standards for the Reporting of Diagnostic Accuracy studies (STARD statement). METHODS: The quality of reporting of diagnostic accuracy studies published in 12 medical journals in 2000 (pre-STARD) and 2004 (post-STARD) was evaluated by two reviewers independently. For each article, the number of reported STARD items was counted (range 0 to 25). Differences in completeness of reporting between articles published in 2000 and 2004 were analyzed, using multilevel analyses. RESULTS: We included 124 articles published in 2000 and 141 articles published in 2004. Mean number of reported STARD items was 11.9 (range 3.5 to 19.5) in 2000 and 13.6 (range 4.0 to 21.0) in 2004, an increase of 1.81 items (95% CI: 0.61 to 3.01). Articles published in 2004 reported the following significantly more often: methods for calculating test reproducibility of the index test (16% vs 35%); distribution of the severity of disease and other diagnoses (23% vs 53%); estimates of variability of diagnostic accuracy between subgroups (39% vs 60%); and a flow diagram (2% vs 12%). CONCLUSIONS: The quality of reporting of diagnostic accuracy studies has improved slightly over time, without a more pronounced effect in journals that adopted the STARD statement. As there is still room for improvement, editors should mention the use of the STARD statement as a requirement in their guidelines for authors, and instruct reviewers to check the STARD items. Authors should include a flow diagram in their manuscript.

Diagnostic Techniques and Procedures↗
PubMed1997

The identification of bias in studies of the diagnostic performance of imaging modalities.

The demand for evidence-based healthcare is increasing nationally and internationally and it is equally necessary in both diagnostic and therapeutic practice. Evidence may be collected and combined by means of a systematic literature review of published and unpublished data on a well-defined topic. The output of such reviews is then available to guide health policy, influence good practice or direct research. Published guidelines are available on the performance of systematic reviews, especially those of randomized controlled trials. Although there is an extensive literature base of research data in diagnostic imaging there are few such trials, but it is still possible to perform systematic reviews. With the alternative study designs encountered it is important to be aware of the main threats to study validity. In this paper the biases likely to be encountered in studies of diagnostic performance are reviewed, with particular reference to diagnostic imaging tests. The biases are sub-divided into three categories. The first category is patient selection and covers the validity of generalizing results beyond the study population. The other two, concerning study design and execution and the interpretation of results, affect the likely validity of the results of a study. An understanding of these factors is an essential prerequisite for those undertaking or using a systematic literature review in the field of diagnostic imaging. The definitions form the foundations of a defensible review protocol.

Bias↗
PubMed2001

Diagnostic decision-making in anatomic pathology.

In diagnostic pathology, decision-making skills are used to match the facts of a particular case to a diagnostic category. Ideally the diagnosis is established with "beyond a reasonable doubt" certainty, but substantial uncertainty orfrank diagnostic error can afflict the diagnostic process for a variety of reasons. Many of these diagnostic problems are explained by failures of decision-making. Unfortunately, it appears that substantial components of decision-making are too poorly understood to study or improve. For example, "instant pattern recognition," use of implicit knowledge, and use of creativity represent areas where discussion may not be helpful. In contrast, rule-based problem-solving is sufficiently well understood that the members of an almost purely cognitive specialty might be prompted to ask, what do we know about what we do when we problem-solve? This article reviews some of the more intriguing aspects of decision-making in the hope of stimulating interest in the topic among pathologists.

Data Collection↗
PubMedDate not supplied

Patient-centered communication and diagnostic testing.

PURPOSE: Although patient-centered communication is associated with improved health and patient trust, information about the impact of patient-centered communication on health care costs is limited. We studied the relationship between patient-centered communication and diagnostic testing expenditures. METHODS: We undertook an observational cross-sectional study using covert standardized patient visits to study physician interaction style and its relationship to diagnostic testing costs. Participants were 100 primary care physicians in the Rochester, NY, area participating in a large managed care organization (MCO). Audio recordings of 2 standardized patient encounters for each physician were rated using the Measure of Patient-Centered Communication (MPCC). Standardized diagnostic testing and other expenditures, adjusted for patient demographics and case-mix, were derived from the MCO claims database. Analyses were adjusted for demographics and standardized patient detection. RESULTS: Compared with other physicians, those who had MPCC scores in the lowest tercile had greater standardized diagnostic testing expenditures (11.0% higher, 95% confidence interval [CI], 4.5%-17.8%) and greater total standardized expenditures (3.5% higher, 95% CI, 1.0%-6.1%). Whereas lower MPCC scores were associated with shorter visits, adjustment for visit length and standardized patient detection did not affect the relationship with expenditures. Total (testing, ambulatory and hospital care) expenditures were also greater for physicians who had lower MPCC scores, an effect primarily associated with the effect on testing expenditures. CONCLUSIONS: Patient-centered communication is associated with fewer diagnostic testing expenditures but also with increased visit length. Because costs and visit length may affect physicians' and health systems' willingness to endorse and practice a patient-centered approach, these results should be confirmed in future randomized trials.

Communication↗
PubMed2006

New rapid diagnostic tests for Neisseria meningitidis serogroups A, W135, C, and Y.

BACKGROUND: Outbreaks of meningococcal meningitis (meningitis caused by Neisseria meningitidis) are a major public health concern in the African "meningitis belt," which includes 21 countries from Senegal to Ethiopia. Of the several species that can cause meningitis, N. meningitidis is the most important cause of epidemics in this region. In choosing the appropriate vaccine, accurate N. meningitidis serogroup determination is key. To this end, we developed and evaluated two duplex rapid diagnostic tests (RDTs) for detecting N. meningitidis polysaccharide (PS) antigens of several important serogroups. METHODS AND FINDINGS: Mouse monoclonal IgG antibodies against N. meningitidis PS A, W135/Y, Y, and C were used to develop two immunochromatography duplex RDTs, RDT1 (to detect serogroups A and W135/Y) and RDT2 (to detect serogroups C and Y). Standards for Reporting of Diagnostic Accuracy criteria were used to determine diagnostic accuracy of RDTs on reference strains and cerebrospinal fluid (CSF) samples using culture and PCR, respectively, as reference tests. The cutoffs were 10(5) cfu/ml for reference strains and 1 ng/ml for PS. Sensitivities and specificities were 100% for reference strains, and 93.8%-100% for CSF serogroups A, W135, and Y in CSF. For CSF serogroup A, the positive and negative likelihood ratios (+/- 95% confidence intervals [CIs]) were 31.867 (16.1-63.1) and 0.065 (0.04-0.104), respectively, and the diagnostic odds ratio (+/- 95% CI) was 492.9 (207.2-1,172.5). For CSF serogroups W135 and Y, the positive likelihood ratio was 159.6 (51.7-493.3) Both RDTs were equally reliable at 25 degrees C and 45 degrees C. CONCLUSIONS: These RDTs are important new bedside diagnostic tools for surveillance of meningococcus serogroups A and W135, the two serogroups that are responsible for major epidemics in Africa.

Africa↗
PubMed2006

Impact of adjustment for quality on results of metaanalyses of diagnostic accuracy.

BACKGROUND: We examined whether and to what extent different strategies of defining and incorporating quality of included studies affect the results of metaanalyses of diagnostic accuracy. METHODS: We evaluated the methodological quality of 487 diagnostic-accuracy studies in 30 systematic reviews with the QUADAS (Quality Assessment of Diagnostic-Accuracy Studies) checklist. We applied 3 strategies that varied both in the definition of quality and in the statistical approach to incorporate the quality-assessment results into metaanalyses. We compared magnitudes of diagnostic odds ratios, widths of their confidence intervals, and changes in a hypothetical clinical decision between strategies. RESULTS: Following 2 definitions of quality, we concluded that only 70 or 72 of 487 studies were of "high quality". This small number was partly due to poor reporting of quality items. None of the strategies for accounting for differences in quality led systematically to accuracy estimates that were less optimistic than ignoring quality in metaanalyses. Limiting the review to high-quality studies considerably reduced the number of studies in all reviews, with wider confidence intervals as a result. In 18 reviews, the quality adjustment would have resulted in a different decision about the usefulness of the test. CONCLUSIONS: Although reporting the results of quality assessment of individual studies is necessary in systematic reviews, reader wariness is warranted regarding claims that differences in methodological quality have been accounted for. Obstacles for adjusting for quality in metaanalyses are poor reporting of design features and patient characteristics and the relatively low number of studies in most diagnostic reviews.

Diagnostic Techniques and Procedures↗